1. Field of the Invention
This invention relates to systems, methods and devices for the treatment of cellular disorders, such as cancer and other hypreproliferative diseases in select tissue in living beings (humans or animals) using real-time scanning, computer analysis and control to visualize, to position and to operate surgical, drug dispensing and imaging devices within the body of the patient. The invention employs a computerized imaging system (such as CAT scan, MRI imaging, ultrasound imaging, infrared, X-ray, UV/visible light fluorescence, Raman spectroscopy, single photon emission computed tomography or microwave imaging) or a combination thereof, to sense the position of diseased tissue within the body of a patient. In a preferred embodiment, the invention provides real-time computer control to maintain and adjust the position of an infusion device, such as a catheter and/or the position of the patient relative to the infusion catheter; and, in one form, also provides real-time computer control of the operation of the infusion catheter based on computer analysis of scanning signals defining images and/or computer models of the dispersion of one or more cytotoxic or other drugs or therapeutically active agents through the vascular bed of the neoplastic tissue being treated. In preferred embodiments of the invention, vasoconstrictive drugs are applied locally based on computer modeling of blood flow patterns in order to channel blood flow carrying the cytotoxic drug or other therapeutic agent into the neoplastic tissue, so as to minimize exposure of healthy tissue to such drugs.
2. Background of the Invention
Chemotherapeutic techniques for the treatment of cancer and other hyperproliferative diseases involving abnormal solid cellular growths using cytotoxic agents have been limited in their effectiveness by difficulties in delivering the agents to the affected tissue; maintaining a therapeutically useful concentration in such tissue and limiting the dispersion of the cytotoxic agent into surrounding, healthy tissue. This problem is especially acute where the cytotoxic agent is one which interferes with cell replication, since certain organs (such as bone marrow) cannot function properly without the rapid proliferation of stem cells. The immune system may be compromised by excessive use (or more precisely, excessive dispersion) of many otherwise-effective cytotoxic agents.
In U.S. Pat. No. 4,978,332 (Luck, et al.), the investigators suggest administering a cytotoxic agent in combination with a vasoconstrictive drug, on the theory that the vasoconstrictive drug will inhibit migration of the cytotoxic drug away from the site of application, which is said to increase its effectiveness.
My co-pending application Ser. No. 08/743,794, filed Nov. 5, 1996, entitled "System and Method For Treating Select Tissue In A Living Being," the disclosure of which is incorporated by reference herein, describes a variety of steerable catheters that can be positioned under computer control near or inside a tumor or other select area of tissue. (It will be understood that, although the word "tumor" is used generally herein, the techniques and systems described are applicable to a variety of neoplastic growths including but not limited to cancer, oncogenically transformed cells, carcinomas, melanomas, lymphomas, myelomas, both benign and malignant tumors, and sarcomas of defined or undefined or irregular shape.) By imaging both the select tissue area of interest within the patient and the location of the catheter itself, real-time adjustments can be made by hand or under computer control in the catheter position to attain and maintain it at a predetermined location relative to a select area within the patient's body, thus facilitating more-precise drug delivery as well as operations, such as laser surgery, on select areas of tissue.
Despite the described and other advances, application of cytotoxic agents and other drugs to tumors or other-diseased areas within the body has not achieved the level of precision needed to use potentially toxic drugs having low therapeutic ratios, with safety. Even if the drug is administered close to the diseased tissue, it may be (and usually is) carried elsewhere by blood circulation before it has had the desired effect at the point of introduction, and in concentrations high enough to do damage elsewhere in the body. There is a need for a system and method for controllably delivering cytotoxic drugs directly to target tissue; and subsequently controlling the diffusion of such drugs so as to maximize their contact (both from a concentration and time standpoint) with the diseased tissue being treated and to minimize contact with healthy tissue elsewhere in the body.